Rev. 01 – October 05

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ITEC Guide to Datacomms

PART 45An Introduction to Smart Homes

The Green Smart Home

This leaflet is produced by EUR ING David Stefanowicz and illustrated by Nancy Satariano BA (Hons)

The ECA ITEC Guide “An Introduction to Smart Homes” mentioned Green Smart Homes usually contain more than just electronic controls and networks; they usually contain advanced building fabrics with excellent thermal properties for walls, ceilings, floors and windows, tight closing external doors and windows, etc. They will always contain an advanced heating and ventilation system often making use of solar, wind or geothermic energy (see Diagram 1). The control systems would usually include presence sensors that switch off lights, turn down heating/cooling and switch off other devices not required in order to minimise energy usage. Electrical lights and appliances are chosen to ensure maximum energy savings and often take other environmental factors into consideration.

Diagram 1These figures were recently published in a national newspaper article

The race against time is on. As the earth’s natural energy resources begin to dwindle, many people and companies have started doing their bit to help prolong our survival by installing ‘green’ energy saving devices in their homes. One of the most popular devices are photovoltaic roofing slates which are designed to withstand the British climate and even storms. Many products have been approved for use in conservation areas and Grade II listed buildings, and have a life expectancy of over 30 years. When laying photovoltaic roof tiles, always ensure that they meet the requirements of BS EN 61215 ‘Crystalline

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Solar powerCan produce electricity or hot water from solar panels on the roof or solar tilesApprox. Cost: £2,000-£4,500 for a hot water system. Solar electricity systems cost up to £7,000 per kilowattApprox. Savings: A solar hot water system could halve hot water bills, cutting £50 from annual energy spending

Rooftop or garden wind turbineWind turbines, 1.5m in diameter, will be available from 2006 and could provide a third of average household electricity consumption. They could become as common a sight as satellite television dishesApprox. Cost: Around £4,000Approx. Savings: Up to £240 a year

Combined heat and power unitReplaces conventional boilers with a unit, which produces heat and electricity by burning gas. Reduces emissions and costs by using waste heat to generate enough electrical power to run several appliances as well as producing heat.Approx. Cost: Around £3,000Approx. Savings: Cuts typical household fuel bills by £150 a year

Ground heat pumpA matrix of underground pipes using a similar principle as a fridge to suck latent heat out of the ground to heat the home. Can provide hot water and central heating, but usually requires special planning permissionApprox. Cost: Around £6,500 to £9,500Approx. Savings: Could cut at least £100 a year off gas bills for heating and hot water

Terrestrial Photovoltaic (PV) Modules – Design qualification and type approval’ and also meet fire proof requirements of BS 476-3 (AA).

The PV tiles generate an annual power of approximately 75kWh/m² giving a potential average value of 1,500 kWh per year (subject to the British weather).

Image provided by solarcentury.com

Another increasingly popular device is the rooftop wind turbine, which was originally designed for yachts. The turbines are usually about 1.5m in diameter and generate about 1.2kW d.c. They are mounted on a swivel bearing which allows the turbine to turn into the wind and make the most of any available breeze. At this stage, the ‘carbonomics’ are against using some of these devices for profit as they can fail to pay their own costs over their lifetime. However, with decreasing production costs and increasing energy prices, the future looks good. One other downside is noise and often the requirements of planning permission depending on the area in which you live.

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Images provided by solarcentury.com

There are a number of combined heat and power (CHP) units already on the market with proven savings and domestic boilers, particularly condensing boilers, which are highly efficient. These units have traditionally been used in tower blocks and consist of either a gas engine or gas turbine with a low pressure boiler fitted on the flue of the primary device. This in turn either produces hot water for the building or drives a low pressure steam turbine which generates more electricity. These devices vary in size from about 50kW upwards. However, a newcomer to the market is a boiler with a micro a.c. alternator which is capable of generating approximately 150W.

Lighting

By using high efficiency lighting such as LED’s, compact fluorescent lamps and photovoltaic garden lighting, you can reduce your lighting energy consumption by up to a factor of 5. Early compact fluorescent lights had a poor rendering (some still do), but nowadays lamps are available with superb colour rendering and there are better designed light fittings which also help produce a better ambience.

Home Controls

There are many home control systems on the market which allow us freedom to roam around the house switching lights on and off as required and turning the heating/air conditioning up and down a few degrees as necessary to make a substantial difference to our energy bills. By carefully controlling the room temperature, one can enjoy both comfort and savings.

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Domestic Appliances

The EU has made life easier for those of us who wish to be ‘greener’. They have produced two labels which help identify products which are more energy efficient and by law these labels must be shown on products, internet adverts, manufacturers’ literature and catalogues, whether for purchase or rental.

The EU Energy label must be displayed on:

Washing MachinesTumble Dryers/Combined Wash-DryersFridges & Fridge-FreezersDish WashersElectric LampsElectric OvensAir Conditioning Units

The label below shows that energy rating ‘A’ is the most energy efficient. Some manufacturers show the goods as A+ or A++ which usually indicates that their product has a higher energy efficiency rating than the minimum required to meet the EU ‘A’ rating (but always seek clarification from the vendor).

The EU energy marking legislation does not cover TV’s, HiFi’s or computers, so do be careful when selecting this type of equipment. In general, LCD style TV’s and monitors

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The European EcolabelSome products are awarded the European Ecolabel which may appear on the label or elsewhere. The Ecolabel indicates that the product has been independently assessed and found to meet strict environmental criteria (considering more than just energy consumption), putting it among the best in its class.

are much more energy efficient than traditional Cathode Ray Tube (CRT) or Plasma screen TV’s, but avoid ‘quick start’ devices which are permanently switched on with only the picture switched off as they use almost all of their normal switched-on power consumption.

Equipment Maintenance

Always remember that if you wish to ensure that your electrical/electronic equipment and installation is safe and operating efficiently, get it serviced regularly as instructed by the manufacturer or installer.

For a quote to turning your house into a greener home look at www.eca.co.uk and look for your nearest ECA member company.

Image provided by solarcentury.com

While every care has been taken to ensure the accuracy of the information contained in this leaflet, neither the authors nor the publishers can accept liability for any inaccuracies in or omissions from the information

provided or any loss or damage arising from or related to its use.

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